Monday, 27 July 2009

Doorstop Heater Block

Wandering B'n'Q the other day, I checked the bargain bin and found this:
From ResistorHeater

It is a brass doorstop: Basically a 1 inch brass rod with a M6 threaded hole down the centre. It's just about the right size to make a heater block! And, it's reduced to £3!
I picked one up to play with.

Closer inspection revealed that the central threaded hole projects all the way through the block, stopping at the small indent for the O-ring.

I hacksawed through at the indent, cutting off a 20mm chunk - the m6 thread goes right through.
I drilled a couple of 6.5mm holes through for my resistors - and widened them a little, as my resistors are not straight, and added a small hole for a themistor.
Widening half the m6 thread to m8 allows me to screw in a Peek insulator.
From ResistorHeater

Here's a pic of the components:
From ResistorHeater

and assembled:
From ResistorHeater

Firing it up, I found that it reaches 220C in about 7 minutes, with no insulation. The heater seems pretty sturdy and well-attached. Starting up my (fixed) BfB extruder drive, I waited expectantly....
From ResistorHeater

Hurrah! It extruded several cm of filament - reasonably quick too!

If it starts up again later, then I might be able to build something soon!

Extrusion: 220C at motor speed of 120/255. Nozzle 0.8mm welding tip, 1.01mm filament

2 comments:

Phil Waud said...

Good effort, well done!

My own Copperlab is about at the stage where Ive got to think about an extruder and Im not exactly impressed by the kits you can buy so it looks like Im going to have to go down the same route. I do have a large chunk of copper (about 40mm diameter and 60mm long), so that might be a starting point.

I notice you still use the long spacers despite having a PEEK insulator - do you find that nescessary or have you just tagged this onto an older extruder?

Renoir said...

Mainly because I've been building different extruders for a while, and it was handy (see earlier post for another version).

The acutal heater and nozzle are a couple of the easier parts to make: the trick is to make it re-start as it can get stuck.

I had most trouble with the drive system, because of one of those intermittent problems. That's probably a good place to start. I know lots of things that I've done wrong - feel free to email/pm me if you want a chat.